COPENHAGEN, Denmark (AP) " "A fatigue fracture" in the main rotor gearbox caused an Airbus helicopter to crash off western Norway in 2016, killing all 13 people on board, Norway's Accident Investigation Board said Thursday.The Airbus EC-225 helicopter was carrying workers from an offshore rig in the North Sea before it went down on Turoey, a tiny island outside Bergen, Norway's second-largest city. Eleven Norwegians, one Briton and one Italian were killed.The helicopter's rotor ...